Pasilla Bajío peppers, also known as chile negro or "little raisin peppers" due to their dark, wrinkled appearance when dried, are a variety of the Capsicum annuum species, famed for their mild to medium heat level, typically ranging from 1,000 to 2,500 Scoville Heat Units (SHU). Originating from Mexico, these peppers are the dried form of the Chilaca pepper and have been integral to Mexican cuisine for centuries, particularly noted in the complex flavors of mole sauces. The name "Pasilla" translates to "little raisin" from Spanish, reflecting their dark, shriveled appearance akin to raisins. Historically, these peppers have been part of the indigenous diet and culinary traditions of Mexico, valued for not just their flavor but also for their nutritional content, including vitamins A, C, and K.